When it comes to building a maternity wardrobe, the smartest approach is to invest in a few truly versatile staples, then accessorize, accessorize, accessorize. One piece that tends to transition nicely throughout the trimesters is a great basic shirtdress in white or black. Here, we've taken Isabella Oliver's chic Una Maternity Shirt Dress ($179) and styled it for five distinctly different phases and occasions. Get inspired, and get shopping!